body {
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: column;
}
header {
  height: 50px;
}
main {
  flex: 1;
}
footer {
  display: flex;
  height: 50px;
  border-top: solid 1px #bbb;
}
footer dl {
  display: flex;
  flex-direction: column-reverse;
  flex: 1;
  background-color: #eee;
  border-right: solid 1px #bbb;
}
footer dl:last-child {
  border-right: none;
}
footer dl dt {
  height: 50px;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-shrink: 0;
  color: #777;
  font-size: 18px;
}
footer dl dt:nth-child(n + 2) {
  border-top: solid 1px #bbb;
  border-right: solid 1px #bbb;
}
